1. Field of the Invention
The present invention relates to a rolling element retainer for a linear displacement apparatus, and more particularly to a rolling element retainer which is disposed between a slide rail and a movable platform and circulates therein to support and move the movable platform.
2. Description of the Prior Art
Commonly, a linear guideway is provided with a movable platform on a slide rail, in order to lower friction and reduce noise, between the slide rail and the movable platform is provided a circulation passage for accommodation of rolling elements, which are commonly balls. Since the rolling elements keep colliding with and rubbing against each other while rolling within the circulation passage, the service life of the rolling elements is greatly reduced. Therefore, a rolling element retainer was developed to limit the position of the respective rolling elements, for example, the ball retainer disclosed in US Pat. No. 2008/0000320A1. This conventional ball retainer is formed with two ball retaining portions disposed at two sides thereof for holding the ball, and a disc on each of its two axial ends. The discs at the two axial ends of one ball retainer are used to insure a smooth contact with another ball retainer while the ball retainers return, so as to reduce abrasion and interference. Nevertheless, neither of the two contacting ball retainers is rotatable, and no ball is disposed between the two contacting ball retainers, therefore, the rolling smoothness and noise problem are still to be improved. Additionally, if the two contacting rolling element retainers are provided with one ball therebetween, it will be impossible to retain the ball, and the balls between the two contacting ball retainers may have difficulty in smoothly passing through the return portion of the circulation passage.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.